As in my prior patents and applications just identified, the present invention has the general objective of improving the performance, power output, flexibility, response and fuel economy of internal combustion engines, epecially two-cycle, variable speed, crankcase compression engines as used for a variety of purposes, for example on motorcycles.
While having important features in common with certain of the prior patents and applications identified above, the present application and its parent application Ser. No. 839,180 contemplate alternative arrangements and further improvements as compared with my earlier patents and applications, as is more fully explained hereinafter with reference to the drawings of the present application.
In considering some of the major general objectives of the invention it is first noted that performance characteristics of engines, and especially of two-cycle engines, are determined in large part by the fuel intake capabilities, which are in turn governed by the total cross-sectional area of the intake passages, the length and the directness of the path of flow of the incoming fuel, the duration of the intake, the portion of the cycle during which intake occurs, and the responsiveness of the action of the intake valves. With these features in mind the present invention, and the inventions of my above identified patents and applications, provide novel arrangements and interrelationships of intake porting and reed valves which mutually contribute to an increase in the cross-sectional intake flow area for the fuel, and to an extension of the portion of the cycle during which intake of fuel occurs, and which shorten and make more direct the flow path of the incoming fuel.
The features of the present invention which contribute to the foregoing general objectives are explained in detail below. However, it is first noted that a brief description of the prior art in this field is included in my prior patents and applications. In this connection see for example the description in my U.S. Pat. No. 3,905,340. For the purposes of the present disclosure, the following brief additional discussion will be helpful as background material.
Important aspects of my developments, disclosed and claimed in my earlier cases, particularly in U.S. Pat. No. 3,905,341 and in applications Ser. No. 674,102 and Ser. No. 586,138, have to do with what I have referred to as "injector" ports, and with the fact that such ports may advantageously be used in combination with other novel intake porting and with the passages commonly used in the industry to transfer the compressed fuel mixture from the crankcase to the combustion side of the piston.
Certain figures of drawings common to my application Ser. No. 586,138 and to U.S. Pat. No. 3,905,341, namely FIGS. 9 and 10, disclose the novel use of injector ports, while FIG. 11 represents, graphically, the improvements, in power curve which are achievable by utilizing one form of injector porting. FIGS. 12 and 13 of my copending application Ser. No. 586,138 disclose another improvement in injector porting. Still other arrangements shown in my application Ser. No. 674,102 also serve these purposes. While these several arrangements of my prior applications have yielded very beneficial results, I have been able to devise apparatus for utilizing injector ports, and novel transfer and intake porting, to still greater advantage, as will now be explained.